The SSD Diaries: Crucial's RealSSD C300
by Anand Lal Shimpi on July 13, 2010 12:39 AM ESTFinal Words
In terms of new, out of box performance, the Crucial RealSSD C300 does very well. It performs like a next generation drive and is significantly faster than Intel's X25-M G2 or anything based on an Indilinx controller. The 128GB C300 tends to be slower than the 100GB SandForce drives while the 256GB C300 is about on par and sometimes faster. The 256GB C300 also pulls ahead if you move to a 6Gbps SATA controller.
For Crucial the achilles heel is our old friend: the read-modify-write, a used C300 can potentially lose a good amount of its initial performance. The major disadvantage for SandForce is if you’re writing perfectly random or highly compressed data. Again I’m talking about data that’s random in nature, not random in terms of access pattern. Our heavy downloading workload shows this best where the 256GB C300 remains on top while the 100GB SandForce drive drops to Indilinx-like performance.
The C300 is clearly a drive made for Windows 7. With no TRIM utility, poor 512-byte aligned performance and clear degradation over time with heavy random writes, the C300 is best used with Windows 7 and its native TRIM support. Luckily for Crucial, there are a lot of Windows 7 users out there. Update: Version 2.6.33 of the Linux kernel supports TRIM as well. Presumably the C300 would do just as well under Linux so long as there's TRIM support.
I often get questions from Mac users asking what the best SSD is for OS X. Since Apple still won’t support TRIM you need a very resilient drive under OS X. That path leads you to SandForce. Pick up a Corsair Force, OCZ Vertex 2, G.Skill Phoenix or whatever SF drive tickles your fancy if you want the best of the best in your Mac.
At last year’s IDF a very smart man put this slide up on a projector:
At the time, the best SSDs offered great peak performance but lost a significant percentage of that over time. The aforementioned smart man then went on to say that Intel is currently playing with technologies that would trade peak performance for better overall performance, not to mention more consistent performance.
Ultimately that’s what bothers me about the C300. In terms of pure performance, in many areas, it’s the drive to beat. The 256GB version performs admirably regardless of workload, and even the 128GB drive is pretty fast. But its performance drop over time just isn’t indicative of a next generation controller. I want to see less of a drop from peak to worst case scenario performance. The larger that hit is, the more write amplification is going on. TRIM fixes much of this but it really depends on the workload. I'd say most desktop users should be fine.
It boils down to this. Crucial is a big company. Micron, its parent, is just plain huge. Despite the early hiccups with the drive I do trust their validation and testing. Even the best fall victim to mistakes. Micron works with enough OEMs to know the importance of shipping stable product. I don’t like that Crucial continued to sell C300s while the drives could potentially brick themselves, but the company gets points for being a name you can trust. Particularly if paired with a good 6Gbps controller, the 256GB C300 is fast. As a result, the C300 is a good balance of high performance and reputable brand.
SandForce on the other hand is much smaller. Most of its validation falls on the shoulders of its partners. And there’s also this nasty habit of selling drives with RC instead of MP (mass production) firmware. Things that wouldn’t fly at Crucial/Micron. But the performance ranges from decent to absolutely amazing depending on the workload. And in terms of degradation over time? I’m almost willing to say that SandForce is simply immune to it. Almost.
So who do you pick? The big company with a controller that behaves more traditionally, yet still tops the charts. Or the smaller company, with a controller that acts more like a rockstar.
If you’re running Windows 7, have a 6Gbps controller and want a 256GB drive, go Crucial. If you’re running any other OS, are using RAID or can only afford a 128GB drive, go SandForce.
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Breit - Tuesday, July 13, 2010 - link
There are 4 different Vertex 2 drives from OCZ as i know:-> the standard Vertex 2, which uses MLC flash and has ~13% overprovisioning (~91GB usable capacity for the 100/128GB model)
-> then there is a Vertex 2e, which is the same as the normal Vertex 2, but with a modified firmware for ~7% overprovisioning (~111GB usable capacity for the 100/128GB model)
-> then there is a Vertex 2 pro, wich also uses MLC flash and also has ~13% overprovisioning, but also has a supercap to help out on a sudden power loss (more like an enterprise feature)
-> and an last there is the Vertex 2 EX: this drive uses SLC flash and therefor is way to expensive for normal desktop use
the first 3 should perform nearly identical. the last is supposed to be quite superior in performance, but i havn't seen any reliable performance numbers as of yet - anand? ;).
hotlips69 - Tuesday, July 13, 2010 - link
Thx for the info!Why would anyone buy the Vertex 2 "standard" over the Vertex "2e" if it performs the same, but has a larger usuable capacity?
Would there not be a performance hit if there is only 7% provisioning compared to 13% if the drive got full???
DanNeely - Tuesday, July 13, 2010 - link
In normal desktop use there's no reason to get the standard drive. Sandforce initially designed its controllers for the enterprise market and servers can be much more brutal on a drive than end user computers are. On a server workload the extra scratch space was useful, but when they moved over to consumer drives it had no benefit. The 2e was released with an updated firmware once it became clear the controller was just wasting space.jedighost - Tuesday, July 13, 2010 - link
Let me answer: there will be OCZ 'Vertex 2' firmware updates coming out that will allow you to "switch" between 100GB and 120GB on the same drive. So far no significant performance difference have been found, but time is an interesting factor here, noone had months or years to test it, and users who visit forums and write their experiences are usually not known for torturing their SSDs 24/7 just to see what happens/kill them/wear them out.Based on the data available at the OCZ Support Forums, grab the 100GB or 120GB version, whichever you can cheaper, and later on you will be able to choose how much provisioning you want, 7 or 13%.
When your 120GB Vertex 2 SSD is full and you write 8GBs of data (7% of 128GB) in a short period, yes, then there can be degradation. But how likely is that, really?
Also, in average, you can write an MLC cell 10,000 times before you wear it out. This means, to evenly wear out all the cells of your Vertex 2, you need to write 10,000x120GB=1200 TERABYTES on your drive. Sure, when you only write a smaller than 4KB file, the whole cell has to be rewritten, but still, as a system drive, which is not supposed to contain huge files, in the size of several Gigs (raided Raptors are for that), when will you write 1000 Terabytes? By that time, your SSD is long outdated, because 10 years passed by.
More concretely: if you write 275 GBs EVERYday to your SSD for 10 years, 365 days a year, then you wrote 1000 TBs. Lets say i didn't calculate with a bunch of factors, and I am wrong to 3:1 degree and your drives wears out in 200TBs, that is 100GBs a day for 10 years. When will you "rewrite" the whole size of your SSD in daily usage?
Catch my drift?
Buy your drive and don't worry, just enjoy it, the same as I did. Have regular backups as this is still new technology, but be ready to be blown away if this is going to be your first SSD - you will realize that it was not stronger CPUs and overclocking that was needed to make a system snappy, but eliminating the most-overlooked bottleneck: the old HDD.
jedighost - Tuesday, July 13, 2010 - link
Actually i made a quick calculation: assuming you can write with 100MB/sec to your Vertex 2 continuously, 24/7, it would still take *120 days* to wear out all the cells, writing to them 10,000 times each. No mortal user had the time to try this yet. :))sor - Saturday, December 11, 2010 - link
FYI, in December '09 Micron announced that their MLC write durability increased significantly. Anything that has their 34nm chips (C300, maybe others) will have much better durability than your figures.Drazick - Tuesday, July 13, 2010 - link
It seems the smart move would be waiting for the next generation of SSD's by Intel.Assuming it would be a SATA 3 drives paired with P65 it should beat anything on the table at the moment.
Jonathan Dum - Tuesday, July 13, 2010 - link
Not to mention 25nm NAND from Intel/Micron... longest wait ever. Though I wonder when all the other guys like OCZ will get 25nm?james.jwb - Tuesday, July 13, 2010 - link
Anand, what are your recommendations for around the 60-80GB mark? Any changes from your conclusion above?Phate-13 - Tuesday, July 13, 2010 - link
I will say it again, and keep saying it till it happens. Most people are not interested in 100-300GB SSD (except for lower prices obviously) or in 30-40GB SSD's. It's the 50-80GB ones that most people are interested in. That's about the sweet spot of capacity that is needed.The Crucial RealSSD C300 64GB is x times more interesting then it's bigger brothers, it's much cheaper, not only in absolute terms, but also in capacity/euro. And by far the best buy atm in my eyes.
The line-up I want to see would be about something like this:
- Kingston V-series S2 64GB
- Western Digital SiliconEdge Blue 64GB
- Crucial RealSSD C300 64GB
- OCZ Solid II 60GB
- OCZ Onyx 64GB
- OCZ Agility 2 60GB
- OCZ Vertex 2 60GB
- Corsair Force 60GB
And perhaps some of the other, cheaper Corsair SSD's.